Burner for liquid fuel



Dec. 21, 1937'. J SP|R|G 2,102,759

BURNER I FOR LIQUID FUEL Filed Jan. 20, 1936 Patented Dec. 21, 1937 UNITED STATES BURNER FOR LIQUID FUEL Josef Spirig, Hard, near Bregenz, Vorarlberg,

,Austria, assignor to Anton Hofstetter, Widnau Switzerland Application January 20, 1936, Serial No. 59,942 In Austria January 22, 1935 3 Claims.

The invention relates to a burner for liquid fuel such as oil and'the like comprising a vaporizer or gasifier externally heated by a combustible mixture. These burners are particularly suitable for furnaces and stoves. Various constructions of such burners have already been proposed which, however, were open to various objections. In most of these knownconstructions there is provided a vaporizer device through the interior of whichextends a vertical oil pipe having a delivering: opening which is located above grooves or recesses, provided in the burner. The vapor- 'izer device is mounted on a supporting plate and between these two members outflow openings are provided for the oil to be gasified in the vaporizer. In order to start such a burner the vaporizer must first be exteriorly heated by a readily burning substance such as alcohol. When then the oil supply is opened the oil falls in drops onto the exteriorly heated vaporizer and is there gasified to a greater or smaller extent. The oil thus gasified escapes through the openings and is ignited near them, so that as the operation is continued the gas itself maintains the vaporizer at the required temperature. Such arrangements are open to the objection, that for starting, another fuel is required than for ordinary operation and furthermore the oil is not completely vaporized. The oil being supplied to the hottest part of the vaporizer, causes only the more volatile constituents of the oil to be gasifled on coming into contact with these red hot parts of the vaporizer since owing to the construction of the latter just referred to the less volatile constituents of the oil flow downwardly and there either form a residue or must be led off by special pipings.

Now the object of the present invention is to enable the burner to be started by means of the same fuel, for instance fuel oil, that is used for ordinaryoperation and to secure the gasification of all the constituents of the fuel. For obtaining this result it is necessary that the fuel be not supplied first to the hotter parts of the va-- porizer, but to the less heated parts. Subsequently the fuel reaches the hotter parts, and thereby completely gasifying the oil. Furthermore it is necessary to so arrange the supply of air that there is an ample air supply at the point where the oil comes first into contact with the vaporizer, and that the air current flows from this point to the hotter parts of the vaporizer. According to the invention this result is secured by providing in a substantially horizontal burner tube a substantially horizontal vaporizer procuring the burner to the furnace door and other 10 details to be more'fully described later on.

The drawing illustrates by way of example a constructional form of the present burner for liqfuel. Fig. 1 is a central longitudinal section of the burner, Fig. 2 is a side elevation of the burner tube and the vaporizer. Fig. 3 is a front elevation of the burner and Fig. 4 is a rear elevation of the parts shown in Fig. 2.

As is seen from the drawing, the burner constructed according to the invention comprises an outer cylindrical burner tube I having a flange 2 near the middle of its length. The inner surface of the burner tube is slightly conical the wall of the burner tube decreasing in thickness from its inner to its outer end. The outer part of the burner tube I from the flange 2 to its front end is solid and has at its front end an inner annular space 5 formed by an inner member 4. In the rear of the flange 2 there are provided in the wall of the burner tube four longitudinal slots 3| separated from each other by four segmental flanges 32, (see Figs. 2 and. 4). Within the burner tube there is mounted a tubular vaporizer 6 connected by ribs 1 with the flanges 32 of the burner tube'l. In the constructional form shown the flange 2, the member 4, the ribs 1, the vaporizer '6 and the rear cover 8 are made integral with the burner tube l. The thickness of the wall of the vaporizer is the same throughout its length and the vaporizer is conical in shape increasing in diameter from the front end to its rear end. Its inner surface is provided with lon gitudinal grooves H separated from each other by ribs I0.

' The front end of the vaporizer is approximately in the same plane as the inner edge of the member 4 and is closed by a cap l2 provided with a central threaded opening into which is screwed the inner end of the fuel oil supply pipe l3. The latter is provided with a delivery nozzle l4 projecting into the vaporizer 6 while to its outer end a bent piece of tubing I5 is secured which is connected in turn by a tubing l6 and a piece of hose H) to a suitable liquid fuel container. An oblong flange 20 is secured to the tubing I6 by a nut I9 and carries two forwardly projecting guide pins 2| guided at their front edges in another oblong flange 22 passing through slots in the wall of the burner tube and axially fixed in position by these slots. Two coiled springs 23 are placed on the guide pins 2| between the fianges 2D and 22 and force the flange 2D and thereby also the closing cap I2 connected thereto against the vaporizer 6. An extension 24, secured to the flange 2, is attached to a fur-, nace door 25 which is adapted to be pushed into a furnace or stove. Thus only half of-the burner projects into the interior of the furnace While the other half together with the hose connection is outside the furnace. Preferably the usual furnace door is removed and the door 25 fitting the burner is mounted in position in place thereof, but the usual furnace door might be provided, if desired, with an opening for the burner to be inserted thereinto.

For starting the burner constructed according to the present invention, liquid fuel is caused to flow into the vaporizer nozzle I4 and collects within the vaporizer 6 until its level reaches the lowermost point of the front opening of the va porizer and then flows out between the cap I2 and the front end of the vaporizer 5, there being provided suitable leakage passages between the two or the cap not properly fitting the front end of the vaporizer as in the case when the two are made of unwrought casting. The liquid fuel thus escaping between the cap I2 and the vaporizer collects at the bottom of the burner tube I and moistens an asbestos wick 25 or the like, which is put onto the bottom. The bottom of the burner tube sloping downwards and forwards, the liquid fuel collects in the front part of the burner tube, where and when the asbestos wick is sufficiently soaked with-the liquid fuel, it is ignited and burns readily since the air enters into the burner in the direction of the arrow 21. The fire is carried to the rear by the air and then passes upwards in the furnace or stove.

Thereby the vaporizer is heated and the liquid fuel contained therein begins to gasify. Then the escape of liquid fuel between the cap I2 and the vaporizer 6 ceases and only gasified fuel escapes therebetween. This being mixed with air, is ignited and heats the vaporizer. The rear end of the vaporizer is highly heated while its front end remains comparatively cool. The fuel first reaching comparatively cool parts of the vaporizer comes into contact with the rear parts of the vaporizer only after having flowed through a comparatively large distance and the vaporizer being moreover closed at its rear end, a complete gasification of all the constituents of the ignited fuel is secured. The object of the longitudinal slots 3i is to cause the gas to be ignited as soon as possible, that is to say immediately after es- "caping fromthe cap I2 in order that the vaporizer may always be surrounded by flames. If the gas pressure within the vaporizer 6 becomes too high the cap I2 may be shifted forward overcoming the pressure of.v the springs 23, whereby the delivery opening is increased. Thereby an automatic safety means against excessive pressure in the vaporizer 6 is provided.

What I claim is:

1. A burner for liquid fuel comprising a burner tube, a vaporizer disposed within said burner tube and spaced therefrom, said vaporizer having its rear end closed and having a resiliently urged cap bearing against its front end and means for leading liquid fuel to said vaporizer.

2. A burner for liquid fuel comprising a burner tube, a vaporizer disposed within said burner tube and spaced therefrom, means for leading liquid fuel to said vaporizer, a cap loosely fitting one end of said vaporizer and means urging said cap against said vaporizer.

- 3. A burner for liquid fuel comprising a burner tube, a vaporizer disposed within said burner tube and spaced therefrom, means for leading liquid fuel to said vaporizer, a cap loosely fitting one end of said vaporizer and spring means urging said cap against said vaporizer.

JOSEF SPIRIG. 

